PIC18F25K22-I/SO Microchip Technology, PIC18F25K22-I/SO Datasheet - Page 327

• Manufacturer Part Number: PIC18F25K22-I/SO
• Description: MCU 8BIT 32KB FLASH 5.5V 28SOIC
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F25K22-I/SO

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 64MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 24
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 19x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Processor Series: PIC18F
• Core: PIC
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164005
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

19.5
Time can be precisely measured after the ratio (C/I) is
measured from the current and capacitance calibration
step by following these steps:
1.
2.
3.
4.
5.
FIGURE 19-3:
 2010 Microchip Technology Inc.
Initialize the A/D Converter and the CTMU.
Set EDG1STAT.
Set EDG2STAT.
Perform an A/D conversion.
Calculate the time between edges as T = (C/I) * V,
where I is calculated in the current calibration step
(Section 19.3.1 “Current Source
C is calculated in the capacitance calibration step
(Section 19.3.2 “Capacitance
V is measured by performing the A/D conversion.
Measuring Time with the CTMU
Module
TYPICAL CONNECTIONS AND INTERNAL CONFIGURATION FOR TIME
MEASUREMENT
CTED1
CTED2
AN
R
PR
X
Calibration”) and
Calibration”),
PIC18(L)FXXK22 Device
EDG2
Preliminary
EDG1
C
AD
A/D Converter
Current Source
CTMU
Output Pulse
It is assumed that the time measured is small enough
that the capacitance, C
to the A/D Converter. For the smallest time measure-
ment, always set the A/D Channel Select register
(AD1CHS) to an unused A/D channel; the correspond-
ing pin for which is not connected to any circuit board
trace. This minimizes added stray capacitance, keep-
ing the total circuit capacitance close to that of the A/D
Converter itself (4-5 pF). To measure longer time
intervals, an external capacitor may be connected to an
A/D channel and this channel selected when making a
time measurement.
PIC18(L)F2X/4XK22
OFFSET
, provides a valid voltage
DS41412D-page 327